U.s. Officials tell us this morning the toothpaste bomb warning is tied to information learned during an array of Europe and elsewhere this week and this past month and that, in fact, the right explosive concealed in just three or four toothpaste tubes could bring down a passenger jet. The urgent alert is meant primarily for the international airlines that are flying into sochi. With athletes and spectators heading to the olympics. Hi. Reporter: Russia had already banned all liquids and gels including toothpaste in carry-on luggage on domestic flights into sochi. I think you're going to see a tightening of the screening procedures on these types of items that could contain explosive devices that could either be used to blow up an airplane going into Russia or be smuggled in to the sochi area for the olympics. Reporter: Bomb experts say just a few tubes of toothpaste could contain as much explosive power as the amount seen in these demonstration tests of the so-called shoe bombs and underwear bombs built by Al Qaeda. A small amount of certain explosives can, in fact, have grave damage and can do grave damage on an aircraft. Reporter: And while the initial warning is connected to the olympics, U.S. Officials say the tas may soon announce additional security precautions at American airports out of an abundance of caution. But authorities say the threat to sochi is very real. The chairman of the house homeland security committee, congressman Michael Mccaul told us the information on the toothpaste bombs in terms of sochi is specific and credible That's planes coming in. Is there any moment at the olympics themselves they're most worried about. We're told that it is not today or tomorrow, that perhaps 48 hours or 72 hours in when security might be lessened. Okay. Brian Ross, thanks very much. All right there, George. To the latest on that powerful winter storm that slammed many areas with more than a foot of snow. ABC's gio Benitez is just outside Philadelphia where so many people have lost power. Good morning, gio. Reporter: Good morning to you, robin. From one of the hardest hit areas in the northeast, the biggest trouble right now. You have ice that brought down so many trees here, also bringing down these power lines and right now, in Pennsylvania alone, we have 500,000 people still in the dark. More than half the nation inundated with snow and ice. A state of emergency in Pennsylvania, iced over trees crashing on to homes. A man helping his neighbor clear debris from his driveway was hit in the head by snapped branches. He was critically injured. Those downed trees plus iced over power lines cutting electricity to more than a million customers throughout the northeast. Villanova university also in the dark, students packing up and heading home. In New York City, heavy, wet snow caused the roof of this home to buckle. The midwest, no better off. Ice storms in southern Michigan leading to this 30-car pileup. Two big rigs mangling a vehicle like it was tin foil. Car parts flung on to guardrails and truckers in central Kansas understandably frightened. I kept seeing 18-wheelers in the ditch. It was getting to where I was almost hitting these vehicles. Reporter: And right now, all across the northeast this morning, we have more than 600,000 people still without power and it could take days, we're told, for the lights to come back on. Robin. Okay, there, gio. We bring in ginger with the latest on this next storm that's coming in. Well, that's what everybody has been talking about. I'll get to it. This is it. 63.6% of the nation is covered in snow, right? That's a lot but it's been a brutal winter. Look at a place like Detroit had 7 inches or so. That makes them 66.7 inches to date. That would be average. So more than 40 inches above where they should be and, yes, the storm that everyone is asking me about, we have seen tweets and social media blowing up with this 3 to 30 inches thing. Look at this. Leaving for the weekend. Can't deal with being noted in with more than 30 inches. That's the worst. Don't worry about it. You won't be. You're not going to get 30 inches of snow. Everybody saw some article printed -- this is a year ago -- and we have been watching the storm Sunday into Monday but that looks like it's falling apart so we're all good. It's just a myth though. Correct. It went on the internet. You promise? I promise. We'll get some snow. We're going to get some light snow. Not 30 inches. Like saying Kate and will are getting married this weekend. That's how old that story is. That's incredible because it was everywhere the last few days. I know. Wow, thank you, ginger. Isn't the internet amazing?

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